When it comes to hot romance fiction, it doesn’t get much hotter than “Fifty Shades of Grey.”

It has dominated global bestseller lists for two years with more than 50 million copies sold, and the movie world is all abuzz with talk of who will play the main characters: sweet, but plain Anastasia Steele and mega-rich, but twisted hunk Christian Grey.

They aren’t the only ones who are hot. The book is getting some heat from a new study that says the novel is rife with emotional and sexual abuse of women.

“ ‘Fifty Shades of Grey’ perpetuates dangerous abuse patterns,” said study author Amy Bonomi, incoming chair and professor of the Department of Human Development and Family Studies at Michigan State University.

The abuse prevalent in the book include stalking, intimidation, threats, isolation and humiliation — all consistent with intimate partner abuse as defined by the U.S. Centers for Disease Control and Prevention, said Bonomi who conducted the study with two other professors at Ohio State University, where she was working.

Their study, titled “Double Crap! Abuse and Harmed Identity in ‘Fifty Shades of Grey,’ ” was published earlier this month in the Journal of Women’s Health.

In the United States, 25 percent of women are victims of intimate partner abuse, Bonomi said. Worldwide, the number is 71 percent.

“We do not want to ban the book. What we do want is for people to understand abuse patterns,” she said. “Just knowing the patterns exist and calling it out is important. I can’t tell you the number of students I’ve had in my classrooms who’ve told me they had no idea what they were experiencing was abuse. Simply being aware is the first step in potentially improving things in your situation.”

Various critics have described the trilogy, full of erotic sex scenes, as sensual and sadistic.

But it’s important for people to recognize that the relationship in the book is abusive and dangerous — even though the series and soon-to-be movie are fiction, Bonomi said. Popular culture and the media images, real or not, that glamorize or belittle violence against women perpetuate a serious global problem.

A representative for E L James, the book’s British author, said James is not doing interviews at this time. But James has previously addressed criticism that her trilogy of books promote sexual abuse.

“People who think that are sort of demonizing women who actually enjoy these kinds of relationships,” James said in an interview with Katie Couric last year. “What people get up to behind closed doors — providing it is safe, sane, consensual and legal — is completely up to them and it’s not for you, I or anybody to judge.”

But Bonomi says it’s that kind of thinking that allows men to get away with violence against women.

“We think if it goes on behind closed doors, it’s nobody’s business. How many murder-suicides do we have to continue to see? If people see someone beating a child hard, they’re likely to step in, say something or report it. That’s not so true when people know a woman is being beaten.”

The relationship between Anastasia and Christian is problematic because there is an unfair balance of power, boundaries are not respected and substance abuse negates consent, Bonomi said.

Cris Sullivan, director of the Research Consortium on Gender-Based Violence at Michigan State University, applauded the study.

Sullivan said she read “Shades of Grey” to see what all the fuss was about.

“I was rather dismayed,” she said. “It symbolizes society’s tolerance for violence against women and lack of awareness, even when they see it.

“This issue is bigger than the book,” said Sullivan, who also chairs the state of Michigan’s domestic violence and sexual assault prevention and treatment board. “It shows that we have a very long way to go [in recognizing sexual violence]. I hope people use this study as an opportunity to further understand and think about this book, especially with a movie coming.”